Designing wireless networks that provide adequate network quality in an operating environment (e.g., an office building) is a non-trivial task. Environmental factors can affect the propagation of radio frequency (RF) waves. For example, walls, doors, windows, and the like can reflect, refract, and attenuate RF waves in ways that may be difficult to predict.
As a result, the operating environment a wireless network is deployed in is a significant variable to consider when designing the wireless network for that environment. The quality of the wireless network may depend on, for example, the number of wireless access points deployed and their respective installation locations.
There are various approaches to designing wireless networks for an environment that consider the propagation of RF waves through the environment.
One approach is a predictive survey in which a wireless network designer predicts how the RF waves will propagate through the environment. For a predictive survey, a designer may simply estimate the maximum range of a wireless access point from an installation location in the environment and provide enough wireless access points to cover the operating environment based on the maximum expected range. The designer may also consider a map of the operating environment and estimate the attenuation expected from structural elements in the environment such as, for example, cement, wood, drywall, etc. Each structural material may be correspond to an expected attenuation value that the designer may consider when estimating the coverage pattern for the wireless access points.
In either case, the designer may not take live measurements within the operating environment for a predictive survey. Instead, the network design is based on the estimations and predictions of the network designer. This approach can be prone to inaccuracies as the estimated range for and attenuation of the RF waves may deviate from the actual range and attenuation. Inaccuracies may thus lead to too many or too few access points and can result in costly revisions to the network design.
Another approach to wireless network design involves live site surveys by professional network designers. During a live site survey, a professional designer installs a wireless access point in the operating environment and measures the signal strength of the access point multiple times to generate a coverage pattern for the wireless access point. Based on the coverage pattern, the professional network designer may determine whether the access point should be moved or whether additional access points are needed to provide adequate coverage and network quality. A live site survey may require multiple iterations before the professional network designer can identify the optimal locations for the wireless access points. This trial-and-error approach may be time consuming when designing networks for large buildings. Furthermore, while a live site survey can produce accurate results, a live site survey may not be a cost-effective approach due to the involvement of professional network designers.
Therefore, a need exists for an accurate and cost-effective approach to designing wireless networks for heterogeneous operating environments.